Air pollution is reaching the menacing level in big cities in Vietnam and the world. This is a judgment from the WHO after analyzing air quality data collected in 1,100 cities of 91 nations from 2003 to 2010. Among these, China and Southeast Asian countries reveal the most serious cases.

WHO’s estimation shows that more than 2 million people around the world die every year because of air pollution, both indoors and outdoors. Inhaling tiny PM10 dust, which can penetrate deeply into human lungs and veins, results in cancer, asthma, cardiac and other respiratory diseases.

The average level of air pollution is currently 15 times higher than the one suggested by WHO (20mcg/m3). In some cities, the level even hits 300mcg/m3 and very few locations are able to maintain the WHO standard level.

According to WHO experts, a shrinkage of the density of PM10 (fine particles of 10 micrometers or less) from 70mcg/m3 to 20mcg/m3 can reduce the death rate caused by air pollution diseases by 15%.

In both developed and developing nations, the factor that contributes chiefly to air pollution stems from transports, industrial manufacturing or simply burning coal for cooking and heating purpose.

In 2008, the number of deaths from air pollution is 1.34 million. If the world followed WHO instruction, around 1.09 million deaths could be prevented this year. Compared with the estimated 1.15 million in 2004, the figure has increased -- due to various reasons like increased pollution or urban population growth.

In a recent environmental conference in Ho Chi Minh City, scientists affirm that 90% of the polluting gas comes from transports. According to the Ho Chi Minh City Department of Transportation, every day 320,000 cars and 3.2 million motorbikes burn millions of liters of fuel, emitting equivalently a massive amount of toxic gas, especially carbon dioxide.

In Ho Chi Minh City air pollution is accelerating at an alarming rate, particularly in the eastern and north-western areas such as Hang Xanh intersection, Dinh Tien Hoang – Dien Bien Phu crossroad and An Suong intersection. The pollution level in these places exceeds the average level by 1.3 to 1.8 times.

In Thu Duc District and district 9, along Ha Noi Highway, especially from Rach Chiec Bridge to Binh Thai intersection, the dust density measured surpasses the permissible level by 1.3 to 7.1 times. This is mainly due to the concentration of many industrial plants in the area.

The downtown section is no exception, particularly along Nam Ky Khoi Nghia Street. The air pollution measured daily at different times shows an excess of 2.5 to 4.5 times greater than what is allowable. The inhabitants here suffer directly from respiratory diseases caused by the dust from transports and construction activities.

In general, Ho Chi Minh City is considered the most seriously polluted city in Vietnam, since its pollution level is 2.5 times higher than the allowable limit.

Doctor Maria Neira, WHO Director for Public Health and Environment, remarks that in many countries air quality requirements have not been set. Even if these requirements are established, the benchmarks and the implementations vary differently between countries.

The measurement of outdoor air pollution in urban areas depends on a number of input factors, ranging from the development background, the source of pollution and the geographic location, as Dr. Carlos Dora, WHO Coordinator for Interventions for Healthy Environment (IHE) points out. The best approach is using WHO data to keep track of the time-trend air pollution in order to detect, improve and intervene effectively.